Means for holding printing plates to rotary presses



A ril 17, 1951 R. R. MYERS, JR 2,549,226

MEANS FOR HOLDING PRINTING PLATES TO ROTARY PRESSES Filed Sept. 27, 19482 Sheets-Sheet 1 T K/i 3)? l// J l 13 4 13 f'zzlenfloz" A ril 17, 1951R. R. MYERS, JR 2,549,226

MEANS FOR HOLDING PRINTING PLATES TO ROTARY PRESSES Filed Sept. 27, 19482 Sheets-Sheet 2 a 2i, 7 4/); Margy Patented Apr. 17, 1951 MEANS FORHOLDING PRINTING PLATES TO ROTARY PRESSES Robert R. Myers, Jr., DesMoines, Iowa Application September 27, 1948, Serial No. 51,466

2 Claims.

The principal object of my invention is to provide a method ofsuccessfully rigidly holding a curved printing plate to a rotary pressduring the printing operation.

A further object of my invention is to provide a means for holdingcurved printing plates to rotary presses that insures against theloosening of the plate during its use on the press.

A still further object of this invention is to provide a means forholding curved printing plates to rotary presses that reduces thecracking and breaking of the plate during the rotating of the press.

A still further object of this invention is to pro vide a means forreducing the wear on curved printing plates.

A still further object of my invention is to pro vide a means for andmethod of successfully holding printing plates to rotary presses thatutilizes present existing printing equipment.

A still further object of my invention is to provide a means for rigidlysecuring curved printing plates to rotary presses that is economical inmanufacture and use.

These and other objects will be apparent to those skilled in the art.

My invention consists in the construction, arrangement, and combinationof the various parts of the device, whereby the objects contemplated areattained as hereinafter more fully set forth, pointed out in my claims,and illustrated in the accompanying drawings, in which:

Fig. 1 is a perspective view of a curved printing plate held to a rotarypress by my method.

Fig. 2 is an enlarged sectional view of the method for rigidly securingthe side of a printing plate to a rotary press and is taken on line 2-2of Fig. 1.

Fig. 3 is an enlarged cross-sectional view of the means shown in Fig. 2,and is taken on line 3-3 of that figure.

4 is an enlarged perspective view of he block means for securing thefront or back end of a curved plate to a press.

Fig. 5 is an enlarged longitudinal sectional view of the block meansused in 1 is taken on line 55 of Fig. 1.

Fig. 6 is a top plan view showing the method of cutting holes in thefront and back of the printing plate.

'7 is a side sectional View of the means shown Fig. 6 and is taken online 5-? of that figure.

One of the problems of rotary printing presses is the securing of thecurved printing plates to the press cylinder. The usual method is tobevel the marginal edges of the plate and use clamps that overlap suchbevel edges and are secured to the drum frame. However, such clamps whenused at the front and back ends of the plate have a tendency to furthercurve the plate and bow its center portion away from the drum press.This means that each time the plate is used for printing, the pressurewill move the center portion in wardly onto the drum frame, and suchconstant bending action causes the plate to rapidly break down and crackalong its transverse center line. Also such clamp blocks rapidly eatinto the soft backing metal of the plate and the plate therefore quicklybecomes loose on the press. This is true of all edge portions of thecurved plate. I

have overcome such problems as will hereinafter be appreciated, butfirst will described presentday equipment and the method of using same.

Referring to the drawings, I have used the numeral Hi to designate acurved printing plate having all of its four side edges I l beveled. Theprinting surface is of the usual hard metal shell, but the major portionis made up of soft metal backing material placed 011 the back of theshell at the time of manufacture. Most all rotary or cylinder pressdrums are of cylindrical construction with spiral grooves 13 cuttherein, or the cylinder may be made of a plurality of spaced apartspiral bars, as shown in Fig. 1, with the groove cut in each of the bars12. Such bars, or cylinders with grooves, have a toothed track M in thebottom of each of the grooves. Also such grooves are of the tongue andgroove type in that each groove has two laterally and oppositelyextending grooves l5 and 16 in its side walls, respectively. It iscommon practice to use clamp blocks ii in such spiral grooves 83. Ingeneral such blocks have a worm gear 19 extending through the bottom ofthe block for engagement with the toothed rack M, and a second worm gear2t in the block and in engagement with the gear 19. A crank or likeWrench 2| is used to manually rotate the worm gear 2!} for moving theblock forwardly or rearwardly in the groove 13, as shown in Fig. 5. Suchblocks also have a rotatably mounted beveled cleat 22 designed tooverlap and engage the beveled portion of a printing plate as shown inthe drawings. The beveled cleat 22 also has two oppositely extendingfinger flanges capable of extending through slits in the block andentering and slidably engaging the grooves l5 and 16, respectively, whenthe beveled cleat is manually rotated to a substantial cross position onthe block.

and tighten onto the bevel I l of the plate.

By rotating the cleat 22, relative to the block, the flanges 23 arewithdrawn from engagement with the side grooves l5 and [5. Usually thebeveled cleat is rotatably mounted on the block directly above the gear20, and a hole 24 is provided through the cleat so that the tool 2| maybe inserted and-reach the bevel gear 20. Usually a second set 25 offinger flanges are rotatably secured in the block, also capable of beingrotated through side slits in the block for engagement with the sidegrooves I5 and It. This rotation of the flanges 25 is accomplished by astud 26 secured thereto and extending to the top surface of the block,as shown in Fig. 1. The head of this stud may be a Phillips type or anysuitable design to take a wrench for operation similar to the rotationof the gear 20. The usual procedure is to place the blocks in the spiralgrooves at all sides of the plate, then rotate the cleats for engagementwith the plate thereby extending the flange fingers 23 into the sidegrooves, also rotating the stud 26 to bring the flange fingers 25 intothe side grooves l5 and I6. The finger flanges 25 are to the rear of thebeveled cleat, to expose the stud 26. With the side grooves i5 and I6 soengaged, the block will be fastened in the groove l3, but may slideforwardly or rearwardly therein, by rotating the worm gears. By somoving the block toward the plate the cleat will overlap This heretoforemeans for securing a plate to a press works somewhat satisfactorily forthe side edges of the curved plate, but when applied to the front andbottom ends of the plate, the tendency is to further how the plate andtrouble quickly results. Even the blocks at the sides of the plate arenot completely successful however. They have a tendency during theprinting phase to bite into and wear the soft backing metal of theplate, whereby the plate will become very loose on the drum after alittle usage. Obviously, when a plate becomes loose, not only willbreakage be possible, but poor printing will result. This is especiallytrue of multicolor printing where the plates must accurately register.

The procedure and equipment heretofore described is common to the artand I lay no claim to the same. My invention resides in slightlychanging the same and making a different setup, whereby the plate willbe successfully and rigidly held on the press throughout the printingphase. I will now explain my invention in detail.

To hold the beveled side edges of the plate to the press I use the samemethod and equipment heretofore described and which is old in the art.However, to prevent the cleats of the block from seriously eating intothe marginal edge portion of the plate, I cast into the two sideportions of the plate at time it is manufactured, a strip of relativelyhard metal 27, such as brass, copper, or like. When the plate is machinebeveled these side strips will be embedded into the relatively softbacking metal of the plate, as shown in Fig. 2. By this arrangement thebeveled holding cleats 22 will contact the relatively hard metal strips21, and will thereby be prevented from eating into the soft backingmetal of the plate. Thus the side edges of the plate will besuccessfully, tightly and rigidly held onto the press and this desirablecondition will continue throughout the printing. Also the aligning ofthe plate on the press will not only be facilitated, but will bemaintained. While this arrangement is successful for the side edges oftheplate, it will not be for the front and rear end edges of the plate,for the simple reason that the rotating of the bevel gears of the blocksat these ends of the plate for moving the blocks toward the plate wouldonly promote the bending of the curved plate. Therefore, to hold thefront and rear edges of the plate to the press, such edges must be drawnin a direction away from the center of the plate, and, not pushed towardthe center as has been done heretofore. To accomplish this, I reversethe blocks at the front and rear ends of the plate, as shown in Fig. land Fig. 5. This places the stud 26 under the marginal edges of theplate. These studs 26 are drilled and topped to take a Phillips or likeheaded screw '28. A hole is formed in and .through the marginal edgeportions of the plate that overlap each of the studs 26. By placing thescrews 28 through these holes in the bottom and top ends of the plate,and threading the same into the prepared studs 26, the upper and lowerend portions of the plate will be rigidly secured to the blocks Hadjacent thereto. By rotating the worm gears of these blocks, they will,due to their reverse arrangement, back away from the plate, therebypulling on the plate from both ends. This action is distinguished fromthe pushing action performed by the blocks at the sides of the plate. 7Obviously, by pulling outwardly on the two ends of the plate it willbeheld tightly and rigidly on the press and all undesirable bowingaction will be elimihated. To remove the plate the screws 28 are removedand the Worm gears of all the blocks are rotated in a direction to causethe blocks to move away from the plate. From the foregoing, it will beappreciated that I have solved the problem of not only successfullyholding the sides of a curved printing plate to a press, but also theends.

One problem, however, is the forming of the holes in the end portions ofthe plate so that they will register with the threaded studs 26. Toaccomplish this, any suitable gauge punch may be used. In the drawings Iuse the numeral 29 to designate the base of such a punch. This base isof a dimension similar to the blocks ll, so that it will fit into andslidably engage a groove i3. It has a mouth 39 to receive the marginaledge of the plate, as shown in Fig. 7. The numeral 3| designates avertical passageway extending through the base and cutting through themouth 33. The numeral 32 designates the punch rod threaded in thepassageway 3! above the mouth and capable of being screwed to a positionwhere its end will pass below the mouth. The position of the verticalpassageway back from the forward end of the base is exactly equal to thedistance from the forward end of a block I! and a screw 28. The numeral33 designates a handle on the punch rod. To cut a hole in the plate itismerely necessary to place the punch means in the groove i3, (which willlater be used by a block I1) and slide the punch toward and onto theplate as far as it will go, and then operate the plate. The punch meansis then removed and upon the placement of a block ll in the groove, itwill be found that the hole 34 formed by the punch will be directly overthe threaded stud 26. The punch rod should also be so formed, as shownin Fig. 7, to form a counter sunk perforation so that the head of thescrew will, when tightened, be flush or below the surface of the plate.

With the block properly under the edge of the plate, it is first screwedforwardly until the cleat contacts the beveled edge of the plate, andcan go no further. Obviously, the punch was also a jig, and at this timethe hole in the plate will be directly over the threaded stud 26. It isthen a simple matter to insert the screw 28 and fasten the block to theprinting plate. After the plate is secured to the blocks by the screws28, the blocks are screwed in the opposite direction to pull the blocksaways from the plate and thereby tighten it on and to the press. Thecleats of these blocks also aid in securing the marginal edge of theplate to these blocks, although the main burden is that of the screws28.

Some changes may be made in the construction and arrangement of mymethod of and means for holding printing plates to rotary pressesWithout departing from the real spirit and purpose of my invention, andit my intention to cover by my claims, any modified forms of structureor use of mechanical equivalents which may be reasonably included withintheir scope.

I claim: g V

i. In combination with a spiral track frame of arotary press; saidspiral track being of a plurality of spiral toothed dovetailed grooves,and a printing plate having reinforcing strips in its side marginaledges, a plurality of block members surroundin said printing plate andslidably resting in some of said dovetailed grooves, rotatable cleats oneach of said block members capable of engagement with the marginal edgeof said printing plate, worm gear means incorporated in each of saidblocks and in engagement with the teeth of the dovetailed groove inwhich they operate,

and screws extending through the upper and lower marginal edge portionsof said plate and operatively threaded into adjacent block members; saidWorm gear means in the blocks at the sides of said plate being used tomove the blocks in a direction toward said plate and the Worm gear meansin the blocks at the upper and lower ends of said plate used to move theblocks in a direction away from said plate.

2. In combination with the frame of a rotary press; said frame being ofa plurality of spaced apart spiral, dovetailed grooves each having teeththerein and a printing plate having spaced apart holes in its upper andlower marginal edge portions, a plurality of block members surroundingsaid printing plate and slidably resting in some of said dovetailedgrooves, rotatable cleats on each of said block members capable ofengagement with the marginal edge of said printing plate, worm gearmeans incorporated in each of said blocks and in engagement with theteeth of the dovetailed groove in which they operate, and screwsextending through the holes in said printing plate and detachablythreaded into adjacent block members; said Worm gear means in the blocksat the sides of said plate being used to move the blocks in a directiontoward said plate and the worm gear means in the blocks at the upper andlower ends of said plate used to move the blocks in a direction awayfrom said plate.

' ROBERT R. MYERS, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:-

UNITED STATES PATENTS Number Name Date 1,961,797 Smith June 5, 19342,180,732 Durham Nov. 21, 1939 2,224,555 Sweet Dec. 10, 1940 2,406,883Luehrs' Sept. 3, 1946

